Page 38 - ARCHIDOCT 6-2

38
ISSN 2309-0103 www.enhsa.net/archidoct Vol. 6 (2) / February 2019
2. Methods
The reason for developing a new design method was to enable a design process where geometric composition, acoustic performance, and robotic fabrication could be explored in parallel.To achieve this the design method is constructed such that the designer, through direct manipulation and de- sign of digital curve geometry, receives the geometric solution that results from milling a wooden plate using the selected curves as milling paths.These milling paths and the given geometric solution allows for both a simulation of the robotic milling process and an acoustic analysis of the milled wooden plate – both simulations holds the potential of acting as valuable feedback for the next iteration of re-designed and increasingly informed curve geometry.
To examine the design method’s ability to assist in the exploration of acoustic geometries and robotic milling of wood panels, the method was implemented in a 3-week design studio with archi- tecture students on their master level.The aim of the design studio was to explore and apply ar- chitectural acoustics in the early design processes through to robotic manufacturing processes and the production of 1:1 prototypes. Structured in three phases the first week explored spatial- and material systems, robotic manufacturing constraints, and parametric modelling. The second week architectural acoustics was introduced together with robotic simulation. During the last week, the students explored their own design systems and iteratively improved the acoustic and manufac- turing performance of their geometric solutions. Each student worked towards a final design for a mobile library shelf system consisting of empty shelfs for books and shelfs containing their acous- tically performative plywood panels.The studio ended with each student fabricating one panel of their own design for mounting in a 1:1 prototype of the mobile library. The design method consists of a computational design system and a physical robotic setup.
The Robotic Setup
The robotic setup consists of an industrial robotic arm (KUKA KR300R2500) with a 7.5KW CNC spindle mounted as its end effector (see figure 1). With a ball nose milling bit (19 mm. diameter) attached to the spindle this setup allows for a milling angle of up to 25 degrees away from the ver- tical axis (z-axis in this case) without colliding with the 800x400x24mm plywood plates that were chosen for the acoustic panels.
The Computational Design System
The computational design system is constructed in Rhino+Grasshopper, and consists of four para- metrically related sub-systems, or clusters, named: Path Generation, Geometry Generation,Acous- tic Analysis, Robotic Simulation.
In the Path Generation cluster, users can directly interface or manipulate with the curve-based milling paths, the paths that the milling robot will follow during fabrication, thereby indirectly con- trolling the appearance of the resulting milling geometry. Design of the milling paths is a three-di- mensional design challenge as the curves can be defined as moving through varying xyz-position, thereby defining their location on the wood plate and the depth they are moving down into the wood plate.There are numerous ways to generate and control curves, making this area open for a creative and explorative design process.
The Geometry Generation cluster performs the subtractive process of removing material. Using the milling paths, their connected planes, the cross section of the chosen milling bit, and the stock
//
Robotic Fabrication of Acoustic Geometries - an explorative and creative design process within an educational context Mads Brath Jensen